Shutter cocking and film transport mechanism for a roll film camera

ABSTRACT

Shutter cocking and film transport mechanism for a roll film camera wherein film cartridges are particularly used, and wherein the film transport is effected with the advance and return strokes of a reciprocating operating slide, the improvement comprising a portion of the shutter cocking and film transport mechanism being used for the film transport consisting of an operating slide (1) traversing a constant path, which is accessible to the user, and a drive element (14) traversing paths of different lengths; and a resilient compensating member (15) is provided between the operating slide (1) and the drive element (14). The compensating member maintains both parts at a distance and bridges their path differences resulting from the increase in diameter of the wound-up film.

States Patent 1 Keiner [111 3,820,143 [4 June 25, 1974 SHUTTER COCKINGAND FILM TRANSPORT MECHANISM FOR A ROLL FILM CAMERA [75] Inventor: HeinzKeiner, Obemdorf, Germany [73] Assignee: Firma Ernst Leitz GmbH,Wetzlar,

Germany [22] Filed: May 25, 1973 [21] Appl. No: 364,147

[30] Foreign Application Priority Data July 24, 1972 Germany 2236255[52] US. Cl. 5 4/ 2 Q [51] Int. Cl. G03b 19/04 [58] Field of Search95/31 [56] References Cited UNITED STATES PATENTS 3,682,066 8/1972 Simon95/31 Primary Examiner-John M. Horan Attorney, Agent, or Firm-Krafft &Wells 5 7] ABSTRACT Shutter cocking and film transport mechanism for aroll film camera wherein film cartridges are particularly used, andwherein the film transport is effected with the advance and returnstrokes of a reciprocating operating slide, the improvement comprising aportion of the shutter cocking and film transport mechanism being usedfor the film transport consisting of an operating slide l) traversing aconstant path, which is accessible to the user, and a drive element (14)traversing paths of different lengths; and a resilient compensatingmember (15) is provided between the operating slide (1) and the driveelement (14). The compensating member maintains both parts at a distanceand bridges their path differences resulting from the increase indiameter of the wound-up film.

5 Claims, 3 Drawing Figures BACKGROUND OF THE INVENTION The field of theinvention is roll holders for different sized films used in photographiccameras.

The invention is particularly concerned with a shutter cocking and filmtransport mechanism for a roll film camera, wherein film cartridges areparticularly employed, and wherein a perforation hole is associated witheach frame in the film, and a locking pin engages this hole at thecorrect position of the frame in the picture gate.

According to West German Pat. No. 1,253,039 of Joachim Madge, having apublication date of Oct. 26, 1967, a reciprocating operating slide isdisclosed, by means of which a camera shutter is cocked and the film istransported. The forward as well as the return stroke of the slide isused by way of coupling elements connected with the slide.

In order to provide an improved force distribution and a more rapidfurther advancement by means of the operating slide, it has also beensuggested in such cameras to place a uniform load on the forward strokeand on the return stroke of the operating slide.

Furthermore, it is conventional to provide the shifting meanscooperating with the operating slide for film transport purposes with aclutch or differential gearing, in order to maintain the operatingstroke of the operating slide at an equal size during all transportstrokes. Without such a differential gearing, the operating stroke ofthe slide would vary constantly, because the slide is in direct gearconnection with the take-up spool of the film, and this take-up spoolexecutes an ever decreasing rotation per transport stroke withincreasing diameter of the roll of film.

Clutches and differential gears, for obtaining a constant operatingstroke per length of film transported, are complicated and are tooexpensive for use in such a camera.

SUMMARY OF THE INVENTION Having in mind the limitations of the priorart, it is an object of the present invention to provide the shuttercocking and film transport mechanism with means which can be simplymanufactured and easily installed, which means ensure a constant lengthof the advance and return strokes of the operating slide and withoutregard to the winding diameter of the take-up spool.

According to the present invention, this object is achieved, in ashutter cocking and film transport mechanism for a roll film camera,wherein film cartridges are particularly used and wherein the filmtransport is effected with the advance stroke and return stroke of areciprocating operating slide, by providing that the part of the shuttercocking and film transport mechanism used for the film transportconsists of an operating slide traversing a constant path. Thisoperating slide is accessible to the user, and a drive element traversesdifferent path lengths and a resilient compensating member is providedbetween the operating slide and the drive element. This member maintainsa distance between the two parts and bridges the difference in the paththereof, which is produced with increasing diameter of the reeled-upfilm.

Furthermore, the present invention provides cooperation between thedrive element, via suitable coupling means, with a gear-wheel of thecamera driving the film take-up spool.

It is advantageous, in this connection, to equip, as provided for in thepresent invention, the drive element with a serrated border which mesheswith the gear wheel driving the film take-up spool of the cartridge.

It is furthermore suggested by the present invention that the springmeans which provides the distance between the operating slide and thedrive element is a compression spring.

BRIEF DESCRIPTION OF THE DRAWINGS The invention is explained hereinbelowin greater detail with reference to a specific embodiment. The drawingsappended hereto show the following:

FIG. 1 is a schematic representation of an operating slide in a planview;

FIG. 2 is a schematic representation of an operating slide withcompensating member in a plan view; and

FIG. 3 shows a section through FIG. 2 along line III- III in a lateralview.

DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIG. 1, an operating slide 1of a roll film camera not shown in detail, wherein film cartridges areparticularly employed, is provided with a cutout 2 in which a rightangled lever 4 mounted on a shaft 3 is engaged. This lever, in turn,cooperates with a locking slide 6 during the shifting movement of theoperating slide 1.

A gear wheel 9, as shown in FIG. 3, is provided in the camera for thetransport of a film 7. This gear wheel engages a film take-up spool 10of a film cartridge 8 and is mounted, together with a further gear wheel11, on a common shaft 12.

A serrated border 13 of a freely movable and resilient profiled member14 meshes with the gear wheel 11. This part 14 is connected with afurther profiled member 16 and is held at a distance therefrom by acompression spring 15. The profiled members 14 and 16, joined by thecompression spring 15, form a compensating member which is entrained bythe operating slide 1 during its film transport and shutter cockingmovement. This is due to the fixed connection between the profiledmember 16 and the operating slide. This compensating member ensures,with an increasing diameter of the reeled-up film, an equally largeadvance and return stroke of the operating slide 1.

A ratchet 17 engaging the gear wheel 11, permits the driving of the filmin one direction only.

The film transport is effected as follows. When the operating slide 1 isactuated in the direction of the arrow (FIG. 1), edge 2a of the cutout 2first engages a leg 4a of the angled lever 4 and moves the same againstthe force of a spring clip 5. During this step, leg 4b of the angledlever 4 presses against angled surface 6a of the locking slide 6 andpulls the same out of perforation 7a of film 7 and thus releases thelatter to be transported out of the film cartridge 8.

Upon the further shifting of the operating slide 1, the serrated border13 of the shaped member 14 engages the gear wheel 11, after apredetermined advancement required for releasing the film as describedabove, and thus transports the film 7 from a film storage reel of thefilm cartridge 8 to its film take-up reel which is not shown in detail(FIGS. 2 and 3). This step is executed via the gear wheel 9 mounted withthe gear wheel 11 on the common shaft 12 which is in engagement with thefilm take-up spool of the film cartridge 8.

During the film transport operation, the locking Slide 6, beingdisengaged from the angled lever 4 after the beginning of the filmtransport, slides along the film. When the subsequent perforated hole 7ais reached, which determines the frame spacing, the locking slide 6,moved by leaf spring 18, engages this hole and arrests the film 7, aswell as the gear wheels 9 and 11 (FIG. 1).

Simultaneously, the ratchet gear 17 engages the gear wheel 11. Thereby,the gear wheels 9 and 11 are blocked against unintended backwardmovement (FIGS. 1 and 2).

Since the frame spacing is determined by the perforated holes 7a, thetransport stroke of the operating slide 1 would become smaller due tothe windup diameter which increases from frame to frame. Thecompensating member 14-16 counteracts this disadvantage.

By arresting the film 7, as well as the gear wheels 9 and 11, theprofiled member 14 cooperating with the gear wheel 11 is likewisebrought to a standstill. The operating slide 1 fixedly joined to theprofiled member 16, however, can still execute its motion into theterminal position, since the further stroke is absorbed by compressingcompression spring 15 and thus the compensation takes place.

By the resilient construction of the profiled member 14, the serratededge 13 is disengaged from the gear wheel 11 during the return stroke ofthe operating slide 1 and returns while ratchetting over the teeth ofgear wheel 11.

At the same time, during the return stroke of the operating lever l, theangled lever 4 is returned to its initial position.

1 claim:

I. In a photographic camera having a roll holder for films, said rollholder being drivingly engaged by gearing means, actuated by means of areciprocating operating slide which transports the film by advance andreturn strokes and cocks the shutter, the improvement comprises a shapedmember (14) having a serrated outer edge 13) for driving said gearingmeans, said operating slide having a given path length, said: shapedmember travelling through a path different in length from said path ofsaid operating slide, and resilient compensating means (15) connectingsaid operating slide and said shaped member to maintain said operatingslide and said shaped member at a distance from one another and bridgingtheir path difference resulting from the increase in diameter of saidfilm (7) as it is rolled on said roll holder.

2. The photographic camera of claim 1, wherein said resilientcompensating means is a compression spring (15).

3. The photographic camera of claim 2, wherein said means for drivingsaid roll holder is a first shaped member (14) having a serrated outeredge (13), a second profiled drive element (16) is attached to saidoperating slide and said first end of the compression spring isconnected to said first shaped member and said second end is connectedto said second profiled drive element.

direction.

1. In a photographic camera having a roll holder for films, said rollholder being drivingly engaged by gearing means, actuated by means of areciprocating operating slide which transports the film by advance andreturn strokes and cocks the shutter, the improvement comprises a shapedmember (14) having a serrated outer edge (13) for driving said gearingmeans, said operating slide having a given path length, said shapedmember travelling through a path different in length from said path ofsaid operating slide, and resilient compensating means (15) connectingsaid operating slide and said shaped member to maintain said operatingslide and said shaped member at a distance from one another and bridgingtheir path difference resulting from the increase in diameter of saidfilm (7) as it is rolled on said roll holder.
 2. The photographic cameraof claim 1, wherein said resilient compensating means is a compressionspring (15).
 3. The photographic camera of claim 2, wherein said meansfor driving said roll holder is a first shaped member (14) having aserrated outer edge (13), a second profiled drive element (16) isattached to said operating slide and said first end of the compressionspring is connected to said first shaped member and said second end isconnected to said second profiled drive element.
 4. The photographiccamera of claim 1, wherein said gearing means comprises a first and asecond gear wheel (11 and 9) mounted on a common shaft (12), and whereinsaid serrated edge meshes with said first gear wheel and said secondgear wheel drives said roll holder.
 5. The photographic camera of claim1, wherein a ratchet (17) engages said first gear wheel to maintain thedirection of revolution of said roll holder in a single direction.